A microwave step thermal imaging detection and tomography method and system

Abstract

The invention discloses a microwave step thermal imagery detection and tomography method and system. The system is composed of a control module, a microwave generation device, a thermal imager, a computer and a plurality of algorithm modules. The method comprises the steps: heating a detected object by means of microwaves and recording transient temperature signals on the surface of the detected object; calculating a second derivative of the transient temperature signals and extracting a peak time as a characteristic value; utilizing the transient temperature signal in a defect-free area as a reference signal, performing a differential calculation for the transient temperature signal in the detected area and the reference signal to obtain a transient differential signal, extracting a separation time and a maximum-value time as the characteristic values; imaging by utilizing the characteristic values and judging whether a defect exists; establishing a quantitative relation between the characteristic values and the depth by virtue of theoretical analysis and testing, and quantifying the depth of an unknown defect; and realizing tomography in different depth ranges by utilizing a temperature rising rate in different time ranges. The method and the system are applicable to the fields such as nondestructive testing, medical imaging and target detection.

Description

technical field [0001] The invention belongs to the technical fields of non-destructive testing, medical imaging and target detection, and in particular relates to a microwave thermal imaging defect detection, tomography and target detection method and system. Background technique [0002] With the development of modern science and industrial technology, non-destructive testing technology has become a necessary means to ensure product quality and equipment operation safety. At present, representative non-destructive testing technologies mainly include radiographic testing, ultrasonic testing, penetrant testing, magnetic particle testing, eddy current testing, and thermal imaging testing. [0003] Thermal imaging inspection technology uses a heat source to heat the inspected object, and uses a thermal imager to observe and record the temperature change information on the surface of the inspected object, so as to detect and evaluate the surface and internal defects of the insp...

AI Technical Summary

Problems solved by technology

The existing microwave thermal imaging defect detection technology has the following deficiencies: 1) The defect detection method relies on the original thermal image and transient temperature curve, which is susceptible to noise interference; 2) There is no effective quantitative method for defect depth; 3) It cannot characterize a specific depth Property changes and implementation tomography

The existing microwave thermal imaging target detection technology also has the same deficiencies as those in the fields of non-destructive testing and medical imaging.

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